Essential oil pharmaceuticals for killing ectoparasites on dogs

BACKGROUND

External parasites, particularly ticks and fleas, are among the most common problems affecting dogs. Chemical medicines are commonly used to prevent and eliminate such external parasites, but their improper use can cause adverse reactions, and the toxins they contain may remain in the environment.

OBJECTIVES

The objective of this study was to investigate the in vitro efficacy of Zanthoxylum limonella, citronella, clove, peppermint, and ginger essential oils against dog ticks and fleas and to test the sensitivity of dogs' skin to these essential oils.

METHODS

The five essential oils were tested for in vitro efficacy against ticks and fleas, and the two most effective essential oils were then tested on the dogs' skin.

RESULTS

The results revealed that these five essential oils at 16% concentrations effectively inhibited the spawning of female engorged ticks. In addition, all five essential oils had a strong ability to kill tick larvae at concentrations of 2% upward. Furthermore, 4% concentrations of the five essential oils quickly eliminated fleas, especially clove oil, which killed 100% of fleas within 1 h. A 50%, 90%, and 99% lethal concentration (LC50, LC90, and LC99) for the essential oils on tick larvae in 24 h were found to be low values. LC50, LC90, and LC99 for the essential oils on flea in 1 h was lowest values. Clove oil at 16% concentration was the most satisfactory essential oil for application on dogs' skin, with a low percentage of adverse effects.

CONCLUSIONS

This study confirmed the effectiveness of essential oils for practical use as tick and flea repellents and eliminators. Essential-oil-based pharmaceutical can replace chemical pesticides and provide benefits for both consumers and the environment.

Gastroprotective effects of Pikad Tri-phol-sa-mut-than herbal remedy on multiple gastric ulcer models in rats

In Thai traditional medicine, Pikad Tri-phol-sa-mut-than has long been used to alleviate gastrointestinal symptoms, renal disease, inflammation-related disorders, and severe malady. This recipe is composed of dried fruits of Morinda citrifolia L., Coriandrum sativum L., and Aegle marmelos (L.) Corrêa. The aim of this study was to assess the anti-gastric ulcer property of the water extract of Pikad Tri-phol-sa-mut-than (TS), using various animal models with different inducers, including restraint water immersion stress, indomethacin, and ethanol/hydrochloric acid (EtOH/HCl). Its mechanisms of anti-gastric ulcer actions were also elucidated using both in vitro and in vivo experiments. When compared with the control groups, the oral pretreatment of TS at the doses of 150, 300 and 600 mg/kg significantly reduced the gastric ulcer formation in all models. It was also found that TS at the dose of 600 mg/kg could increase gastric wall mucus in rats but could not produce the significant reduction of the gastric volume or total acidity of gastric content. Results from hematoxylin and eosin (H&E) and Periodic acid-Schiff (PAS) staining examinations of gastric tissues confirmed that TS visibly reduced gastric mucosal damage, while immunohistochemistry revealed that TS remarkably suppressed the protein expression of Bcl-2-associated X (BAX), a regulator of apoptosis, compared to those of the control group. The DPPH, ABTS, and FRAP assays showed antioxidant effects of TS. All of these findings demonstrated that TS has gastroprotective effects, which may be related to the increase in the gastric wall mucus secretion, not anti-secretory activity, as well as its antioxidant and antiapoptotic activities.

Anti-Inflammatory, Antinociceptive, Antipyretic, and Gastroprotective Effects of Eurycoma longifolia Jack Ethanolic Extract

Tongkat ali (Eurycoma longifolia Jack) (ELJ) is a plant in the Simaroubaceae family. Its roots are used in traditional Thai medicine to treat inflammation, pain, and fever; however, the antiulcer abilities of its ethanolic extract have not been studied. This study examined the anti-inflammatory, antinociceptive, antipyretic, and gastroprotective effects of ethanolic ELJ extract in animal models and found that ELJ effectively reduced EPP-induced ear edema in a dose-dependent manner and that a high dose of ELJ inhibited carrageenan-induced hind paw edema formation. In cotton-pellet-induced granuloma formation, a high dose of ELJ suppressed the increases in wet granuloma weight but not dry or transudative weight. In the formalin-induced nociception study, ELJ had a significant dose-dependent inhibitory impact. Additionally, the study found that yeast-induced hyperthermia could be significantly reduced by antipyretic action at the highest dose of ELJ. In all the gastric ulcer models induced by chemical substances or physical activity, ELJ extracts at 150, 300, and 600 mg/kg also effectively prevented gastric ulcer formation. In the pyloric ligation model, however, the effects of ELJ extract on gastric volume, gastric pH, and total acidity were statistically insignificant. These findings support the current widespread use of Eurycoma longifolia Jack in traditional medicine, suggest the plant's medicinal potential for development of phytomedicines with anti-inflammatory, antinociceptive, and antipyretic properties, and support its use in the treatment of gastric ulcers due to its gastroprotective properties.

HPLC and DNA barcoding profiles for identification of the selected twelve Mucuna species and its application for detecting prohibited aphrodisiac Mucuna products

Aphrodisiac herbal products originated from various plants including Mucuna species. In Thai folklore, Mucuna macrocarpa Wall. and M. pruriens (L.) DC. have long been consumed and utilized for their aphrodisiac properties. Consumption of these plants can lead to serious adverse effects caused by l-dopa. The plants have been legally banned for use as foods, dietary supplements, or nutraceuticals by the FDA of several countries. To protect consumers, methods for the identification of illicit plants or herbal products are needed. This study aimed to identify the selected twelve Mucuna species and examine the aphrodisiac herbal products containing M. macrocarpa and M. pruriens by using HPLC analysis of l-dopa coupled with DNA barcoding profiles of ITS, matK, rbcL, and trnH-psbA. The results showed that l-dopa could be found not only in the seeds of M. macrocarpa and M. pruriens but also in associated allied Mucuna species. Then, a DNA barcode was introduced to support in HPLC profiling to identify the plants. DNA barcodes of twelve Mucuna species found in Thailand were established and used to reconstruct a phylogenetic tree. In this study, ITS2 sequences showed the highest interspecific variability and could be used to differentiate all Mucuna species. The results of ITS2 sequence coupled with HPLC analysis revealed that all the purchased aphrodisiac products originated from M. pruriens only. Therefore, the integration of HPLC analysis and DNA barcoding profile was an efficient method for the identification of prohibited Mucuna species for safety monitoring of herbal supplements and protecting customer safety. Regulatory agencies should raise awareness and restrain the use of these commercial products.

Antiallergic activities of shallot (Allium ascalonicum L.) and its therapeutic effects in allergic rhinitis

BACKGROUND

Onion has antiallergic activity but lack of evidence for shallot.

OBJECTIVE

To determine whether shallot owns similar antiallergic activity to onion and its therapeutic effects in allergic rhinitis when added to standard treatment.

METHODS

In-vitro β-hexosaminidase inhibitory activities of shallot was compared with onion on RBL-2H3 cells. In clinical study, a randomized, double-blind, placebo-controlled trial was performed. Sixteen AR patients were randomized equally into the controls who received cetirizine 10 mg once daily and placebo capsules for 4 weeks, and the treatment who received 3g of oral shallot per day (equivalent to 1 ½ bulbs) and cetirizine. Visual analog scores of overall symptoms (VAS), total nasal and ocular symptom scores (TNSS and TOSS), nasal airway resistance (NAR), and adverse events were assessed.

RESULTS

Shallot extract at 200 μg/mL had an average β-hexosaminidase inhibition rate of 97% while onion extract had 73%. HPLC chromatograms (λ = 290nm) of both plants showed nearly identical patterns of quercetin compounds, such as quercetin 3,4'-diglucoside, quercetin 4'-glucoside, and quercetin. After 4-week of treatment, 62.5% of patients in shallot group and 37.5% of patients in control group showed improvement of post-treatment VAS. TNSS were significantly reduced in both groups, however no difference between groups (P = 0.18). TOSS were significantly improved only in the shallot group (P = 0.01). Adverse events from shallot were not different from placebo.

CONCLUSIONS

Shallot had antiallergic activity and similar quercetin compounds to onion. The shallot oral supplement and cetirizine was shown to improve the overall AR symptoms more than cetirizine alone.

Anti-inflammatory effects of Pikad Tri-phol-sa-mut-than remedy, consisting of dried fruits of Aegle marmelos (L.) Corrêa, Coriandrum sativum L., and Morinda citrifolia L

ETHNOPHARMACOLOGICAL RELEVANCE

Inflammation has been known to possess some essential roles in many diseases, especially those with chronic or severe conditions. Pikad Tri-phol-sa-mut-than, a Thai traditional herbal remedy, has long been used to treat gastrointestinal sicknesses, fever, and severe illness caused by the deformities of Tridosha. In particular, this recipe has also been applied for inflammation-related conditions including gout and rheumatoid arthritis. The Pikad Tri-phol-sa-mut-than recipe consists of dried fruits of three herbs including Aegle marmelos (L.) Corrêa, Morinda citrifolia L., and Coriandrum sativum L. Each of these plant components of Pikad Tri-phol-sa-mut-than exhibited anti-inflammatory activities. However, anti-inflammatory effect of Pikad Tri-phol-sa-mut-than remedy has not been reported.

AIM OF THE STUDY

The objective of this study was to elucidate the anti-inflammatory activities of Pikad Tri-phol-sa-mut-than extract (TS) against acute and chronic inflammation in rats.

MATERIALS AND METHODS

To study the effects of TS on acute inflammation, ethyl phenylpropiolate (EPP)-induced ear edema, carrageenan- and arachidonic acid (AA)-induced hind paw edema models were carried out. In addition, cotton pellet-induced granuloma formation was performed to specify the inhibitory effects of TS on chronic inflammation.

RESULTS

The topical application of TS significantly inhibited EPP-induced ear edema in rats. In the carrageenan- and AA-induced paw edema models, the oral administration of TS significantly reduced paw volumes, compared to those of the control groups. In addition, the 7-day oral treatment of TS demonstrated a significant suppressive effect on cotton pellet-induced granuloma formation.

CONCLUSIONS

The current study revealed that TS possesses anti-inflammatory activities against acute and chronic inflammation. Our studies support the use of TS in traditional medicine, and the development of TS as a novel natural product for treating diseases associated with inflammation.

Topical Gynura procumbens as a Novel Therapeutic Improves Wound Healing in Diabetic Mice

Nonhealing wounds are major socioeconomic challenges to healthcare systems worldwide. Therefore, there is a substantially unmet need to develop new drugs for wound healing. Gynura procumbens, a herb found in Southeast Asia, may be an effective therapeutic for nonhealing diabetic wounds. The aim of this study was to evaluate the efficacy of G. procumbens on wound healing in the diabetic milieu. G. procumbens extract was obtained using 95% ethanol and its components were determined by thin layer chromatography. Diabetes was induced in mice using streptozotocin. We found that G. procumbens extract contained stigmasterol, kaempferol and quercetin compounds. Topical application of G. procumbens on the wounded skin of diabetic mice accelerated wound healing and induced the expression of angiogenin, epidermal growth factor, fibroblast growth factor, transforming growth factor and vascular endothelial growth factor. Furthermore, G. procumbens promoted in vitro wound healing and enhanced the migration and/or proliferation of human endothelial cells, fibroblasts, keratinocytes and mast cells cultured in diabetic conditions. Finally, G. procumbens promoted vascular formation in the diabetic mice. To the best of our knowledge, this is the first study that evaluates in vivo wound healing activities of G. procumbens and activation of cells involved in wound healing process in diabetic conditions. The findings that G. procumbens accelerates wound healing and activates cells involved in the wound healing process suggest that G. procumbens might be an effective alternative therapeutic option for nonhealing diabetic wounds.

Volatile profiles from over-ripe purée of Thai mango varieties and their physiochemical properties during heat processing

This research investigated volatile profiles of over-ripe Thai mango purée during thermal processing by solid-phase extraction, volatile quantification by XAD-2-solvent extraction, as well as descriptive sensory analysis. Overripe fruits of three varieties were analyzed for the ripening stage using specific gravity as well as firmness and the physiochemical properties were also reported. We found that aromatic profiles could be used as true representative to describe Thai mango identities of each varieties. A simple and straightforward heat treatment had differing effects on aroma characteristics and those effects were dependent with mango varieties. Indeed, the amount of terpene hydrocarbons and oxygenated sesquiterpenoids alternated after heat treatment. All descriptive attributes of heated ‘sam-pee’ purée were intensified while, heat treatment significantly improved only “mango identity” in ‘maha-chanok’ and “fermented” odour in ‘keaw’ purée. With or without heat treatment, the volatile profiles of ‘maha-chanok’ remained quite stable while heating played a significant role on chemical ingredients of ‘keaw’ and ‘sam-pee’. Our study demonstrated that the manufacturing of the over-ripe mango into the products of high market value, selection of varieties is vitally important based upon their specific aroma characteristics before and after processing.

Mucuna pruriens (L.) DC. seed extract inhibits lipopolysaccharide-induced inflammatory responses in BV2 microglial cells

ETHNOPHARMACOLOGICAL RELEVANCE

Inflammation caused by activated microglia is known to be associated with neurodegenerative diseases, e.g., Parkinson's disease (PD) and Alzheimer's disease (AD). Inhibiting the inflammatory process can be considered a potential strategy for the treatment of inflammation-associated diseases. Mucuna pruriens (L.) DC. (Leguminosae) has long been used in Thailand, India, China and other tropical countries to treat several diseases including PD. M. pruriens seeds have been found to possess a variety of pharmacological properties including antioxidant and anti-Parkinsonism effects. However, the anti-inflammatory effects of M. pruriens seeds during microglial activation have yet to be reported.

AIM OF THE STUDY

The present study was performed to evaluate the anti-inflammatory effects of M. pruriens seed extract and elucidate its underlying mechanism using lipopolysaccharide (LPS)-stimulated BV2 microglial cells.

MATERIALS AND METHODS

BV2 microglial cells were pretreated with various concentrations of M. pruriens seed extract before being stimulated with LPS. The levels of inflammatory mediators were analyzed by Griess assay and enzyme-linked immunoassay (ELISA). The protein expression levels of inflammatory cytokines were determined by Western blot analysis. The translocation of nuclear factor-kappa B (NF-κB) was assessed by immunofluorescence microscopy.

RESULTS

M. pruriens seed extract significantly inhibited the release of inflammatory mediators including nitric oxide (NO), IL-1β, IL-6, and TNF-α in LPS-stimulated BV2 microglial cells. The extract also decreased the protein expression of IL-1β, IL-6, and TNF-α. Moreover, M. pruriens seed extract inhibited the translocation of NF-κB.

CONCLUSIONS

M. pruriens seed extract could suppress inflammatory responses in LPS-activated BV2 microglial cells by inhibiting the NF-κB signaling pathway. These findings support the use of M. pruriens seeds in traditional and alternative medicine for the treatment of PD and other inflammation-associated diseases.

Chemical Constituents, Antioxidant, Anti-MMPs, and Anti-Hyaluronidase Activities of Thunbergia laurifolia Lindl. Leaf Extracts for Skin Aging and Skin Damage Prevention

This study aimed to investigate the potential usage of Thunbergia laurifolia Lindl. leaf extracts in the cosmetic industry. Matrix metalloproteinases (MMPs) and hyaluronidase inhibition of T. laurifolia leaf extracts, prepared using reflux extraction with deionized water (RE) and 80% v/v ethanol using Soxhlet's apparatus (SE), were determined. Rosmarinic acid, phenolics, and flavonoids contents were determined using high-performance liquid chromatography, Folin-Ciocalteu, and aluminum chloride colorimetric assays, respectively. Antioxidant activities were determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and linoleic acid-thiocyanate assays. MMP-1 inhibition was investigated using enzymatic and fluorescent reactions, whereas MMP-2, MMP-9, and hyaluronidase inhibition were investigated using gel electrophoresis. Cytotoxicity on human fibroblast cell line was also investigated. The results demonstrated that SE contained significantly higher content of rosmarinic acid (5.62% ± 0.01%) and flavonoids (417 ± 25 mg of quercetin/g of extract) but RE contained a significantly higher phenolics content (181 ± 1 mg of gallic acid/g of extract; p < 0.001). SE possessed higher lipid peroxidation inhibition but less DPPH• scavenging activity than RE. Both extracts possessed comparable hyaluronidase inhibition. SE was as potent an MMP-1 inhibitor as gallic acid (half maximal inhibitory concentration values were 12.0 ± 0.3 and 8.9 ± 0.4 mg/cm3, respectively). SE showed significantly higher MMP-2 and MMP-9 inhibition than RE (p < 0.05). Therefore, SE is a promising natural anti-ageing ingredient rich in rosmarinic acid and flavonoids with antioxidant, anti-hyaluronidase, and potent MMPs inhibitory effects that could be applied in the cosmetic industry.

Free Radical Scavenging Capability of Various Defatted Sesame Seed Cakes and Hulls Using EPR Compared with In Vitro Testing and HPLC Analysis

The free radical scavenging activities of black and white sesame seed hulls and the powder of black and white sesame seed cakes were investigated using noninvasive continuous wave electron paramagnetic resonance (EPR) and antioxidant assays. With black sesame seed hulls and the powder of black sesame seed cakes, EPR detected the very strong single-line signal intensities that correspond to the stable organic radicals, while the spectrum of the white sesame seed hulls and the white sesame seed cakes showed no signal. The in vitro antioxidant activities of black and white sesame seed cake extract were evaluated by DPPH free radical scavenging activity, hydrogen peroxide scavenging activity, and ferric reducing antioxidant power (FRAP) assay. The results indicated that the extract from black sesame seed cake possessed a greater DPPH radical inhibitory activity and hydrogen peroxide inhibitory activity than white sesame seed cake extract, with IC₅₀ values of 0.847 ± 0.011 mg/mL and 0.338 ± 0.007 mg/mL, respectively. Black sesame seed cake extract also showed a strong reducing power with a FRAP value of 1.307 ± 0.037 mM Fe (II)/g of extract weight and an EC₁ value of 0.683 ± 0.002 mg/mL. The main compounds from the black and white sesame seed cake extracts were analysed using high-performance liquid chromatography (HPLC). The results revealed that the main compounds in black and white sesame seed cake extracts were in a group of water-soluble lignans, mainly sesaminol triglucoside and sesaminol diglucoside. However, sesaminol diglucoside was found in large amounts in the black sesame seed cake extract, while it was found in a very small amount in the white sesame seed cake extract. Therefore, these results demonstrated considerable antioxidant capacity of the sesame seed, especially in the black strain.

Acute effects of essential oil blend containing phlai oil on mood among healthy male volunteers: Randomized controlled trial

Background Essential oil blend (ESOB) containing Zingiber montanum or Phlai and Zingiber tenuiscapus oils as the major components has high levels of terpenes such as sabinene, terpinene, terpinolene, and terpine-4-ol. Phlai is well known for its analgesic property, but its effects on mood remain unclear. This study aimed to investigate the acute effects of inhaling the ESOB containing phlai essential oils on mood and stress among healthy volunteers. Methods A prospective, randomized, double-blinded, controlled trial pilot study was conducted among 38 healthy male volunteers; 19 in the ESOB containing phlai oil group and 19 in the control group, which used olive oil. One single inhalation was provided continuously for 15 min via hot steam. Mood status was assessed pre- and post-intervention using the Visual Analog Scales for Mood, Anxiety, Stress and Alertness (MASA). Rorschach tests, in a modified analysis, were also employed. One-way ANCOVA was used to determine statistical differences of the mood test results between ESOB containing phlai oil and olive oil. Results Mean age of the participants was 22.11 (SD 2.1) years. Both ESOB containing phlai oil and olive oil increased the post-test scores of positive mood and reduced the scores of negative mood. However, no difference was observed regarding the mood test scores between groups, except concerning the Rorschach stress test (F (1,38)=6.486, p=0.015). The variance of change, explained by the model (R square), was 32.8%, while the adjusted R-squared was 0.290. Conclusions Single inhalation aromatherapy using ESOB containing phlai oil or olive oil showed an immediate improvement of mood states among healthy young male volunteers by easing the negative emotions and enhancing positive emotions, especially feelings of pleasure and contentment. Natural blend of phlai essential oils was more efficacious than olive oil in reducing emotional stress.

Caesalpinia sappan: A promising natural source of antimicrobial agent for inhibition of cariogenic bacteria

From the previous findings, the ethanolic fractionated extract of Caesalpinia sappan (F-EtOH) has high activity against Streptococcus mutans, the most severe cariogenic bacteria. The present study was aimed to isolate and identify the active compound of F-EtOH and compare its inhibitory activity against the biofilm of S. mutans as well as the cytotoxicity to oral fibroblast cells with F-EtOH. Compound isolation was done by column chromatography. The active compound was identified using liquid chromatography-mass spectrometry with electrospray ionization and nuclear magnetic resonance spectroscopy. It was found that the major compound of F-EtOH is brazilin. F-EtOH and brazilin were compared for inhibitory potential on the biofilms of three strains of S. mutans. The results exhibited that both F-EtOH and brazilin had potential on inhibiting biofilm formation and eradicating the preformed biofilms and their activity was dose dependent. F-EtOH showed significantly less toxic to normal periodontal ligament fibroblast than brazilin. At low concentration of 1- and 2-MBC, F-EtOH showed higher effective than brazilin. The results of our study suggest that the antibacterial activity of F-EtOH is according to the synergistic effects of the existing compounds including brazilin in F-EtOH.

A significant mechanism of molecular recognition between bioflavonoids and P-glycoprotein leading to herb-drug interactions

Inhibition of P-glycoprotein (P-gp)'s function may conduct significant changes in the prescription drugs' pharmacokinetic profiles and escalate potential risks in taking place of drug/herb-drug interactions. Computational modeling was advanced to scrutinize some bioflavonoids which play roles in herb-drug interactions as P-gp inhibitors utilizing molecular docking and pharmacophore analyses. Twenty-five flavonoids were utilized as ligands for the modeling. The mouse P-gp (code: 4Q9H) was acquired from the PDB. The docking was operated utilizing AutoDock version 4.2.6 (Scripps Research Institute, La Jolla, CA) against the NBD2 of 4Q9H. The result illustrated the high correlation between the docking scores and observed activities of the flavonoids and the putative binding site of these flavonoids was proposed and compared with the site for ATP. To evaluate hotspot amino acid residues within the NBD2, Binding modes for the ligands were achieved using LigandScout to originate the NBD2-flavonoid pharmacophore models. The results asserted that these inhibitors competed with ATP for binding site in the NBD2 (as competitive inhibitors) including the hotspot residues which associated with electrostatic and van der Waals interactions with the flavonoids. In MD simulation of eight delegated complexes selected from the analyzed flavonoid subclasses, RMSD analysis of the trajectories indicated the residues were stable throughout the duration of simulations.

Insight into the molecular mechanism of P-glycoprotein mediated drug toxicity induced by bioflavonoids: an integrated computational approach

In this work, molecular docking, pharmacophore modeling and molecular dynamics (MD) simulation were rendered for the mouse P-glycoprotein (P-gp) (code: 4Q9H) and bioflavonoids; amorphigenin, chrysin, epigallocatechin, formononetin and rotenone including a positive control; verapamil to identify protein-ligand interaction features including binding affinities, interaction characteristics, hot-spot amino acid residues and complex stabilities. These flavonoids occupied the same binding site with high binding affinities and shared the same key residues for their binding interactions and the binding region of the flavonoids was revealed that overlapped the ATP binding region with hydrophobic and hydrophilic interactions suggesting a competitive inhibition mechanism of the compounds. Root mean square deviations (RMSDs) analysis of MD trajectories of the protein-ligand complexes and NBD2 residues, and ligands pointed out these residues were stable throughout the duration of MD simulations. Thus, the applied preliminary structure-based molecular modeling approach of interactions between NBD2 and flavonoids may be gainful to realize the intimate inhibition mechanism of P-gp at NBD2 level and on the basis of the obtained data, it can be concluded that these bioflavonoids have the potential to cause herb-drug interactions or be used as lead molecules for the inhibition of P-gp (as anti-multidrug resistance agents) via the NBD2 blocking mechanism in future.

Potential of native Thai aromatic plant extracts in antiwrinkle body creams

Antioxidant activities of 10 essential oils and 10 absolutes extracted from Thai aromatic plants were evaluated and compared to thyme oil, trolox, quercetin, and kaempferol by two independent assays: the 2, 2-diphenyl-1-1-picrylhydrazyl (DPPH*) radical scavenging assay and the thiobarbituric acid reactive species (TBARS) assay for lipid peroxidation. We found that four essential oils including ginger oil (Zingiber officinale Roscoe), Wan-sao-long leaf oil (Amomum uliginosum Koen), lemongrass oil (Cymbopogon citratus), holy basil oil (Ocimum sanctum L.), and the absolute of dwarf ylang-ylang [Cananga odorata Hook. f. & Thomson var. fruticosa (Craib) J. Sinclair] exhibited high antioxidant activity in both DPPH and TBARS assays and possessed satisfactory fragrance properties. These were then combined into an essential oil blend (EOB) and retested for antioxidant activity. The EOB also exhibited high antioxidant activity in the above assays. It was then incorporated into a stable cream base as EOB body cream. The EOB body cream was found to be best able under storage in stress conditions and presented significantly higher antioxidant activity than its' cream base both before and after stability testing. The effect of EOB body cream on skin surface topography was evaluated in 29 healthy volunteers using the Skin Visiometer (SV 600 FW, CK Electronic GmbH, Germany). Three parameters, Ra, Rz (roughness), and surface, were analyzed. After 4 weeks of application, the EOB body cream showed significant reductions in surface and Rz compared with before treatment (p < 0.05, paired t-test), and with untreated and placebo treatment (p < 0.05, Duncan test). These results indicate that the essential oils and absolutes from Thai plants may serve as potential sources of natural antioxidants for spa and cosmetic products designed to prevent or treat signs of skin aging.

Appraisal of biological activities and identification of phenolic compound of African marigold (Tagetes erecta) flower extract

The flowers of African marigold (Tagetes erecta L), a medicinal plant widely cultivated in Thailand, were subjected to evaluation for total phenolics, DPPH scavenging and thiobarbituric acid-reactive substance (TBARs) assays as well as tyrosinase inhibitory activity. In preliminary studies, the ethyl acetate (EA) extract obtained by continuous extraction showed the highest activities with highest phenolic content among all extracts. Bioassay-guided fractionation of EA extract led to isolation of a flavonoid identified as quercetagetin. Interestingly, it was found that quercetagetin exhibited potent DPPH scavenging activity with IC50 of 3.70 μg/ml which is about 2-3 times higher activity than standard quercetin (IC50 5.07 μg/ml) and trolox (IC50 9.93 μg/ml). Moreover, it exhibited tyrosinase inhibitory activity on L-tyrosine (IC50 89.31 μg/ml), higher than α- and β-arbutins (IC50 157.77 and 222.35 μg/ml) and slightly higher (IC50 128.41 μg/ml) than ellagic acid (IC50 151.1 μg/ml) when using L-DOPA as substrate. Testing with skin fibroblasts, all the extracts and quercetagetin demonstrated no toxic effect. These finding strongly indicate that African marigold flower is a promising source of natural antioxidative and tyrosinase inhibitory substances with safe to skin.

Chemical composition and antibacterial activity of rhizome oils from five Hedychium species

The essential oils from rhizomes of five Hedychium species, H. coronarium, H. neocarneum, H. flavescens, H. speciosum and H. stenopetalum (Zingiberaceae), were obtained by hydrodistillation and analyzed by capillary GC and GC/MS. Sixty components were identified and percentage oil yields from the fresh plants ranged from 0.06-0.17 % (v/w). All rhizome oils were rich in terpenes, especially monoterpenes (75.0-95.9 %). The most common compounds in the rhizome oils of Hedychium were beta-pinene, linalool and 1,8-cineole. The essential oils were tested against four bacterial strains. They showed moderate to weak activity against Gram-positive bacteria (inhibition zone 25-13 mm, MIC 0.3-8.3 mg/mL, MBC 0.6-8.3 mg/mL).

Chemical Composition and Antibacterial Activity of Rhizome Oils from Five Hedychium Species

The essential oils from rhizomes of five Hedychium species, H. coronarium, H. neocarneum, H. flavescens, H. speciosum and H. stenopetalum (Zingiberaceae), were obtained by hydrodistillation and analyzed by capillary GC and GC/MS. Sixty components were identified and percentage oil yields from the fresh plants ranged from 0.06-0.17 % (v/w). All rhizome oils were rich in terpenes, especially monoterpenes (75.0-95.9 %). The most common compounds in the rhizome oils of Hedychium were β-pinene, linalool and 1,8-cineole. The essential oils were tested against four bacterial strains. They showed moderate to weak activity against Gram-positive bacteria (inhibition zone 25-13 mm, MIC 0.3-8.3 mg/mL, MBC 0.6-8.3 mg/mL).

Isoflavonoids from Pueraria mirifica and their estrogenic activity

Nine isoflavonoids including a new pterocarpene, puemiricarpene, were isolated from the tuberous root of Pueraria mirifica (Leguminosae). The structure of puemiricarpene was determined by spectroscopic means. Estrogenic activity of the isolated isoflavonoids was tested using MCF-7 human breast cancer cells. Moderate activity was observed for kwakhurin, a prenylated isoflavonoid.

Identification of deoxymiroestrol as the actual rejuvenating principle of "Kwao Keur", Pueraria mirifica. The known miroestrol may be an artifact

Miroestrol (1) has been isolated previously as an active principle from "Kwao Keur" (Pueraria mirifica), a rejuvenating folk medicine from Thailand. Reinvestigation using bioassay-guided purification has resulted in the isolation of a new potent phytoestrogen, deoxymiroestrol (2). The facile aerial oxidation of 2 into 1 suggests the possibility that 1 may be an artifact.

Isolation of pyropheophorbide a from the leaves of Atalantia monophylla (ROXB.) CORR. (Rutaceae) as a possible antiviral active principle against herpes simplex virus type 2

Antiviral activity-guided isolation studies on the leaves of Atalantia monophylla (ROXB.) CORR. (Rutaceae) led to the identification of pyropheophorbide a (1), a simple chlorin derivative, from the chloroform extract (fr. B) as a possible antiviral active principle against herpes simplex virus type 2 (HSV-2). Pyropheophorbide a methyl ester (2) was also isolated from the hexane extract (fr. A).